Zinc

Zinc cannot be found in its native ore and is usually associated with lead deposits and sometimes with silver. There are various ores of zinc, four of which are essential to prospectors. You may find the word calamine in geological writings and it many times appears as an ore of zinc. It used to be utilized by the English to refer to smithsonite and the Americans used to call it hemimorphite. Hemimorphite is usually white but sometimes it can be found in yellow, brown green or blue color. it has a glassy luster to it, a hardness of 4.5 to 5 and a specific gravity of 3.4 to 3.5. Smithsonite is a zinc carbonate that has a yellow, gray, green, brown or white color to it and it can sometimes be confused for quartz that has the same color but it can be identified because of its hardness. It has a vitreous luster, a hardness of 5 and a specific gravity of 4.3 to 4.4. Sphalerite is commonly known as zinc blende and is the more valuable ore of zinc. It has a sixty seven percent of the metal as well as gallium, indium and cadmium, and it is also the main ore of those metals. It can usually be found in crystal form and usually has a black color to it. It sort of looks like galena however it can be tested to make sure. It has a resinous luster to it, a hardness of 3.4 to 4 and a specific gravity of 3.9 to 4.1. Hydrozincite is considered a secondary ore of zinc and it commonly occurs in climates that are arid. It does not have a crystal structure and will become a bright blue under an ultraviolet light. It has a dull luster, a hardness of 2.5 to 5 and a specific gravity of 3.6 to 3.8.